*model 1
xtpcse expend lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp ///
 mmm,  p c(ar1)
 
 *model 2
 xtpcse expend lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp ///
 mmm ssdpct,  p c(ar1)
 
 *model 3
 xtpcse expend lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp   ///
 ssdpct mmmXssdpct,  p c(ar1)
 
 *model 4
xtpcse pctsocprot2 lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp ///
 mmm,  p c(ar1)
 
*model 5 
 xtpcse pctsocprot2 lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp ///
mmm ssdpct,  p c(ar1)
 
* model 6
xtpcse pctsocprot2 lgdppc  lgrowth lunemp pop65 ltrade linfl election purepres enpp   ///
ssdpct mmmXssdpct,  p c(ar1)
 
